The invention relates to a multi-pole conductor line. Such conductor lines are known, for example, from DE 103 59 541 A1 and from DE 199 17 309 A1. Here, it involves an extruded plastic profile in which the busbars of the conductor line are arranged insulated from each other. The profile is made from a plurality of chambers of which one group is open toward the front side of the profile. In the chambers of this group, the busbars are arranged and accessible from the open front side for the current collector of a vehicle traveling along the conductor line. Two other groups of chambers that are closed in cross section form the rear base of the profile and the insulation between the busbars, respectively.
Conductor lines of this type generally have a total length that makes it necessary to arrange several insulating profiles one after the other at the end faces. Here, a mechanically stable connection between the individual insulating profiles of a conductor line must be created, wherein suitable connection elements are used. For engaging such connection elements, a corresponding shaping of the end regions of the insulating profiles is necessary that cannot be performed in the scope of the extrusion, but instead requires later processing, which increases the production expense.
In addition, there is the problem that, at the connection points between the individual insulating profiles of a conductor line, the insulating effect is broken. There, the lengths of the air gaps and creep paths between the individual busbars, i.e., the shortest paths between the surfaces of two adjacent busbars through free space or along the surface of the insulating profile, which are specified by the cross-sectional shape along an insulating profile, no longer intersect. Instead, at such a connection point, if additional measures are not taken, the length of the air gap is given by the direct distance of two adjacent busbars and the length of the creep path is given by the shortest path between two adjacent busbars on the end face of the insulating profile. These lengths effective at a connection point are generally significantly shorter than the corresponding lengths along the insulating profile.
The lengths of the air gaps and creep paths are subject to appropriate safety regulations that must be observed under the aspect of product liability, and, indeed, along an entire conductor line, i.e., also at said connection points. This is naturally more difficult to achieve if the total dimensions of a conductor line are to be more compact.
One possibility for extending the air gaps and creep paths at the connection points between the individual insulating profiles to safety-regulation values consists in the joining of additional insulating elements in this region in the course of the assembly of the individual insulating profiles. For this purpose, the end regions of the insulating profiles must be prepared for holding said insulating elements, wherein additional expense is incurred in the production of the insulating profiles. This applies especially when later processing of the insulating profiles must be performed on the end faces.
In the present context, the large difference between the coefficients of thermal expansion of the metallic busbars, which are typically made from copper, and the insulating profiles made from plastic represents another problem. Due to the sometimes considerable length of a conductor line, this would lead to thermally induced longitudinal stresses of enormous magnitude, if countermeasures in the form of providing expansion joints were not taken. At such expansion joints, the problem of interrupting the insulation effect of the insulating profiles presents itself in intensified form, because here a gap of considerable and also variable extent between two successive insulating profiles must be taken into account and must be corrected in terms of insulation.
In view of these conditions, one problem of the invention is to specify a novel and useful solution for the connection of successive insulating profiles of a multi-pole conductor line, with this solution guaranteeing a sufficient length of the air gaps and creep paths between the busbars of the conductor line and being distinguished through a lowest possible processing expense in the assembly.